xref: /linux/drivers/net/ethernet/aquantia/atlantic/aq_ring.c (revision 93a3545d812ae7cfe4426374e00a7d8f64ac02e0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Atlantic Network Driver
3  *
4  * Copyright (C) 2014-2019 aQuantia Corporation
5  * Copyright (C) 2019-2020 Marvell International Ltd.
6  */
7 
8 /* File aq_ring.c: Definition of functions for Rx/Tx rings. */
9 
10 #include "aq_ring.h"
11 #include "aq_nic.h"
12 #include "aq_hw.h"
13 #include "aq_hw_utils.h"
14 #include "aq_ptp.h"
15 
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 
19 static inline void aq_free_rxpage(struct aq_rxpage *rxpage, struct device *dev)
20 {
21 	unsigned int len = PAGE_SIZE << rxpage->order;
22 
23 	dma_unmap_page(dev, rxpage->daddr, len, DMA_FROM_DEVICE);
24 
25 	/* Drop the ref for being in the ring. */
26 	__free_pages(rxpage->page, rxpage->order);
27 	rxpage->page = NULL;
28 }
29 
30 static int aq_get_rxpage(struct aq_rxpage *rxpage, unsigned int order,
31 			 struct device *dev)
32 {
33 	struct page *page;
34 	int ret = -ENOMEM;
35 	dma_addr_t daddr;
36 
37 	page = dev_alloc_pages(order);
38 	if (unlikely(!page))
39 		goto err_exit;
40 
41 	daddr = dma_map_page(dev, page, 0, PAGE_SIZE << order,
42 			     DMA_FROM_DEVICE);
43 
44 	if (unlikely(dma_mapping_error(dev, daddr)))
45 		goto free_page;
46 
47 	rxpage->page = page;
48 	rxpage->daddr = daddr;
49 	rxpage->order = order;
50 	rxpage->pg_off = 0;
51 
52 	return 0;
53 
54 free_page:
55 	__free_pages(page, order);
56 
57 err_exit:
58 	return ret;
59 }
60 
61 static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
62 			  int order)
63 {
64 	int ret;
65 
66 	if (rxbuf->rxdata.page) {
67 		/* One means ring is the only user and can reuse */
68 		if (page_ref_count(rxbuf->rxdata.page) > 1) {
69 			/* Try reuse buffer */
70 			rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
71 			if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
72 				(PAGE_SIZE << order)) {
73 				self->stats.rx.pg_flips++;
74 			} else {
75 				/* Buffer exhausted. We have other users and
76 				 * should release this page and realloc
77 				 */
78 				aq_free_rxpage(&rxbuf->rxdata,
79 					       aq_nic_get_dev(self->aq_nic));
80 				self->stats.rx.pg_losts++;
81 			}
82 		} else {
83 			rxbuf->rxdata.pg_off = 0;
84 			self->stats.rx.pg_reuses++;
85 		}
86 	}
87 
88 	if (!rxbuf->rxdata.page) {
89 		ret = aq_get_rxpage(&rxbuf->rxdata, order,
90 				    aq_nic_get_dev(self->aq_nic));
91 		return ret;
92 	}
93 
94 	return 0;
95 }
96 
97 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
98 				       struct aq_nic_s *aq_nic)
99 {
100 	int err = 0;
101 
102 	self->buff_ring =
103 		kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
104 
105 	if (!self->buff_ring) {
106 		err = -ENOMEM;
107 		goto err_exit;
108 	}
109 	self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
110 					   self->size * self->dx_size,
111 					   &self->dx_ring_pa, GFP_KERNEL);
112 	if (!self->dx_ring) {
113 		err = -ENOMEM;
114 		goto err_exit;
115 	}
116 
117 err_exit:
118 	if (err < 0) {
119 		aq_ring_free(self);
120 		self = NULL;
121 	}
122 
123 	return self;
124 }
125 
126 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
127 				   struct aq_nic_s *aq_nic,
128 				   unsigned int idx,
129 				   struct aq_nic_cfg_s *aq_nic_cfg)
130 {
131 	int err = 0;
132 
133 	self->aq_nic = aq_nic;
134 	self->idx = idx;
135 	self->size = aq_nic_cfg->txds;
136 	self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
137 
138 	self = aq_ring_alloc(self, aq_nic);
139 	if (!self) {
140 		err = -ENOMEM;
141 		goto err_exit;
142 	}
143 
144 err_exit:
145 	if (err < 0) {
146 		aq_ring_free(self);
147 		self = NULL;
148 	}
149 
150 	return self;
151 }
152 
153 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
154 				   struct aq_nic_s *aq_nic,
155 				   unsigned int idx,
156 				   struct aq_nic_cfg_s *aq_nic_cfg)
157 {
158 	int err = 0;
159 
160 	self->aq_nic = aq_nic;
161 	self->idx = idx;
162 	self->size = aq_nic_cfg->rxds;
163 	self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
164 	self->page_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
165 			       (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
166 
167 	if (aq_nic_cfg->rxpageorder > self->page_order)
168 		self->page_order = aq_nic_cfg->rxpageorder;
169 
170 	self = aq_ring_alloc(self, aq_nic);
171 	if (!self) {
172 		err = -ENOMEM;
173 		goto err_exit;
174 	}
175 
176 err_exit:
177 	if (err < 0) {
178 		aq_ring_free(self);
179 		self = NULL;
180 	}
181 
182 	return self;
183 }
184 
185 struct aq_ring_s *
186 aq_ring_hwts_rx_alloc(struct aq_ring_s *self, struct aq_nic_s *aq_nic,
187 		      unsigned int idx, unsigned int size, unsigned int dx_size)
188 {
189 	struct device *dev = aq_nic_get_dev(aq_nic);
190 	size_t sz = size * dx_size + AQ_CFG_RXDS_DEF;
191 
192 	memset(self, 0, sizeof(*self));
193 
194 	self->aq_nic = aq_nic;
195 	self->idx = idx;
196 	self->size = size;
197 	self->dx_size = dx_size;
198 
199 	self->dx_ring = dma_alloc_coherent(dev, sz, &self->dx_ring_pa,
200 					   GFP_KERNEL);
201 	if (!self->dx_ring) {
202 		aq_ring_free(self);
203 		return NULL;
204 	}
205 
206 	return self;
207 }
208 
209 int aq_ring_init(struct aq_ring_s *self)
210 {
211 	self->hw_head = 0;
212 	self->sw_head = 0;
213 	self->sw_tail = 0;
214 
215 	return 0;
216 }
217 
218 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
219 				       unsigned int t)
220 {
221 	return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
222 }
223 
224 void aq_ring_update_queue_state(struct aq_ring_s *ring)
225 {
226 	if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
227 		aq_ring_queue_stop(ring);
228 	else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
229 		aq_ring_queue_wake(ring);
230 }
231 
232 void aq_ring_queue_wake(struct aq_ring_s *ring)
233 {
234 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
235 
236 	if (__netif_subqueue_stopped(ndev,
237 				     AQ_NIC_RING2QMAP(ring->aq_nic,
238 						      ring->idx))) {
239 		netif_wake_subqueue(ndev,
240 				    AQ_NIC_RING2QMAP(ring->aq_nic, ring->idx));
241 		ring->stats.tx.queue_restarts++;
242 	}
243 }
244 
245 void aq_ring_queue_stop(struct aq_ring_s *ring)
246 {
247 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
248 
249 	if (!__netif_subqueue_stopped(ndev,
250 				      AQ_NIC_RING2QMAP(ring->aq_nic,
251 						       ring->idx)))
252 		netif_stop_subqueue(ndev,
253 				    AQ_NIC_RING2QMAP(ring->aq_nic, ring->idx));
254 }
255 
256 bool aq_ring_tx_clean(struct aq_ring_s *self)
257 {
258 	struct device *dev = aq_nic_get_dev(self->aq_nic);
259 	unsigned int budget;
260 
261 	for (budget = AQ_CFG_TX_CLEAN_BUDGET;
262 	     budget && self->sw_head != self->hw_head; budget--) {
263 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
264 
265 		if (likely(buff->is_mapped)) {
266 			if (unlikely(buff->is_sop)) {
267 				if (!buff->is_eop &&
268 				    buff->eop_index != 0xffffU &&
269 				    (!aq_ring_dx_in_range(self->sw_head,
270 						buff->eop_index,
271 						self->hw_head)))
272 					break;
273 
274 				dma_unmap_single(dev, buff->pa, buff->len,
275 						 DMA_TO_DEVICE);
276 			} else {
277 				dma_unmap_page(dev, buff->pa, buff->len,
278 					       DMA_TO_DEVICE);
279 			}
280 		}
281 
282 		if (unlikely(buff->is_eop)) {
283 			++self->stats.tx.packets;
284 			self->stats.tx.bytes += buff->skb->len;
285 
286 			dev_kfree_skb_any(buff->skb);
287 		}
288 		buff->pa = 0U;
289 		buff->eop_index = 0xffffU;
290 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
291 	}
292 
293 	return !!budget;
294 }
295 
296 static void aq_rx_checksum(struct aq_ring_s *self,
297 			   struct aq_ring_buff_s *buff,
298 			   struct sk_buff *skb)
299 {
300 	if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
301 		return;
302 
303 	if (unlikely(buff->is_cso_err)) {
304 		++self->stats.rx.errors;
305 		skb->ip_summed = CHECKSUM_NONE;
306 		return;
307 	}
308 	if (buff->is_ip_cso) {
309 		__skb_incr_checksum_unnecessary(skb);
310 	} else {
311 		skb->ip_summed = CHECKSUM_NONE;
312 	}
313 
314 	if (buff->is_udp_cso || buff->is_tcp_cso)
315 		__skb_incr_checksum_unnecessary(skb);
316 }
317 
318 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
319 int aq_ring_rx_clean(struct aq_ring_s *self,
320 		     struct napi_struct *napi,
321 		     int *work_done,
322 		     int budget)
323 {
324 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
325 	bool is_rsc_completed = true;
326 	int err = 0;
327 
328 	for (; (self->sw_head != self->hw_head) && budget;
329 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
330 		--budget, ++(*work_done)) {
331 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
332 		bool is_ptp_ring = aq_ptp_ring(self->aq_nic, self);
333 		struct aq_ring_buff_s *buff_ = NULL;
334 		struct sk_buff *skb = NULL;
335 		unsigned int next_ = 0U;
336 		unsigned int i = 0U;
337 		u16 hdr_len;
338 
339 		if (buff->is_cleaned)
340 			continue;
341 
342 		if (!buff->is_eop) {
343 			buff_ = buff;
344 			do {
345 				next_ = buff_->next,
346 				buff_ = &self->buff_ring[next_];
347 				is_rsc_completed =
348 					aq_ring_dx_in_range(self->sw_head,
349 							    next_,
350 							    self->hw_head);
351 
352 				if (unlikely(!is_rsc_completed))
353 					break;
354 
355 				buff->is_error |= buff_->is_error;
356 				buff->is_cso_err |= buff_->is_cso_err;
357 
358 			} while (!buff_->is_eop);
359 
360 			if (!is_rsc_completed) {
361 				err = 0;
362 				goto err_exit;
363 			}
364 			if (buff->is_error ||
365 			    (buff->is_lro && buff->is_cso_err)) {
366 				buff_ = buff;
367 				do {
368 					next_ = buff_->next,
369 					buff_ = &self->buff_ring[next_];
370 
371 					buff_->is_cleaned = true;
372 				} while (!buff_->is_eop);
373 
374 				++self->stats.rx.errors;
375 				continue;
376 			}
377 		}
378 
379 		if (buff->is_error) {
380 			++self->stats.rx.errors;
381 			continue;
382 		}
383 
384 		dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
385 					      buff->rxdata.daddr,
386 					      buff->rxdata.pg_off,
387 					      buff->len, DMA_FROM_DEVICE);
388 
389 		/* for single fragment packets use build_skb() */
390 		if (buff->is_eop &&
391 		    buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
392 			skb = build_skb(aq_buf_vaddr(&buff->rxdata),
393 					AQ_CFG_RX_FRAME_MAX);
394 			if (unlikely(!skb)) {
395 				err = -ENOMEM;
396 				goto err_exit;
397 			}
398 			if (is_ptp_ring)
399 				buff->len -=
400 					aq_ptp_extract_ts(self->aq_nic, skb,
401 						aq_buf_vaddr(&buff->rxdata),
402 						buff->len);
403 			skb_put(skb, buff->len);
404 			page_ref_inc(buff->rxdata.page);
405 		} else {
406 			skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
407 			if (unlikely(!skb)) {
408 				err = -ENOMEM;
409 				goto err_exit;
410 			}
411 			if (is_ptp_ring)
412 				buff->len -=
413 					aq_ptp_extract_ts(self->aq_nic, skb,
414 						aq_buf_vaddr(&buff->rxdata),
415 						buff->len);
416 
417 			hdr_len = buff->len;
418 			if (hdr_len > AQ_CFG_RX_HDR_SIZE)
419 				hdr_len = eth_get_headlen(skb->dev,
420 							  aq_buf_vaddr(&buff->rxdata),
421 							  AQ_CFG_RX_HDR_SIZE);
422 
423 			memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
424 			       ALIGN(hdr_len, sizeof(long)));
425 
426 			if (buff->len - hdr_len > 0) {
427 				skb_add_rx_frag(skb, 0, buff->rxdata.page,
428 						buff->rxdata.pg_off + hdr_len,
429 						buff->len - hdr_len,
430 						AQ_CFG_RX_FRAME_MAX);
431 				page_ref_inc(buff->rxdata.page);
432 			}
433 
434 			if (!buff->is_eop) {
435 				buff_ = buff;
436 				i = 1U;
437 				do {
438 					next_ = buff_->next,
439 					buff_ = &self->buff_ring[next_];
440 
441 					dma_sync_single_range_for_cpu(
442 							aq_nic_get_dev(self->aq_nic),
443 							buff_->rxdata.daddr,
444 							buff_->rxdata.pg_off,
445 							buff_->len,
446 							DMA_FROM_DEVICE);
447 					skb_add_rx_frag(skb, i++,
448 							buff_->rxdata.page,
449 							buff_->rxdata.pg_off,
450 							buff_->len,
451 							AQ_CFG_RX_FRAME_MAX);
452 					page_ref_inc(buff_->rxdata.page);
453 					buff_->is_cleaned = 1;
454 
455 					buff->is_ip_cso &= buff_->is_ip_cso;
456 					buff->is_udp_cso &= buff_->is_udp_cso;
457 					buff->is_tcp_cso &= buff_->is_tcp_cso;
458 					buff->is_cso_err |= buff_->is_cso_err;
459 
460 				} while (!buff_->is_eop);
461 			}
462 		}
463 
464 		if (buff->is_vlan)
465 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
466 					       buff->vlan_rx_tag);
467 
468 		skb->protocol = eth_type_trans(skb, ndev);
469 
470 		aq_rx_checksum(self, buff, skb);
471 
472 		skb_set_hash(skb, buff->rss_hash,
473 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
474 			     PKT_HASH_TYPE_NONE);
475 		/* Send all PTP traffic to 0 queue */
476 		skb_record_rx_queue(skb,
477 				    is_ptp_ring ? 0
478 						: AQ_NIC_RING2QMAP(self->aq_nic,
479 								   self->idx));
480 
481 		++self->stats.rx.packets;
482 		self->stats.rx.bytes += skb->len;
483 
484 		napi_gro_receive(napi, skb);
485 	}
486 
487 err_exit:
488 	return err;
489 }
490 
491 void aq_ring_hwts_rx_clean(struct aq_ring_s *self, struct aq_nic_s *aq_nic)
492 {
493 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
494 	while (self->sw_head != self->hw_head) {
495 		u64 ns;
496 
497 		aq_nic->aq_hw_ops->extract_hwts(aq_nic->aq_hw,
498 						self->dx_ring +
499 						(self->sw_head * self->dx_size),
500 						self->dx_size, &ns);
501 		aq_ptp_tx_hwtstamp(aq_nic, ns);
502 
503 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
504 	}
505 #endif
506 }
507 
508 int aq_ring_rx_fill(struct aq_ring_s *self)
509 {
510 	unsigned int page_order = self->page_order;
511 	struct aq_ring_buff_s *buff = NULL;
512 	int err = 0;
513 	int i = 0;
514 
515 	if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
516 					   self->size / 2))
517 		return err;
518 
519 	for (i = aq_ring_avail_dx(self); i--;
520 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
521 		buff = &self->buff_ring[self->sw_tail];
522 
523 		buff->flags = 0U;
524 		buff->len = AQ_CFG_RX_FRAME_MAX;
525 
526 		err = aq_get_rxpages(self, buff, page_order);
527 		if (err)
528 			goto err_exit;
529 
530 		buff->pa = aq_buf_daddr(&buff->rxdata);
531 		buff = NULL;
532 	}
533 
534 err_exit:
535 	return err;
536 }
537 
538 void aq_ring_rx_deinit(struct aq_ring_s *self)
539 {
540 	if (!self)
541 		goto err_exit;
542 
543 	for (; self->sw_head != self->sw_tail;
544 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
545 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
546 
547 		aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
548 	}
549 
550 err_exit:;
551 }
552 
553 void aq_ring_free(struct aq_ring_s *self)
554 {
555 	if (!self)
556 		goto err_exit;
557 
558 	kfree(self->buff_ring);
559 
560 	if (self->dx_ring)
561 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
562 				  self->size * self->dx_size, self->dx_ring,
563 				  self->dx_ring_pa);
564 
565 err_exit:;
566 }
567